transparent wood

Transparent wood

April 25, 2025 By EarthWise Leave a Comment

Plastics are pretty much everywhere in the modern world including places we want them to be and places where we don’t. Conventional plastics are not biodegradable and instead cause increasing problems wherever they end up after their useful life. As a result, there are global efforts to find environmentally friendly replacements for petroleum-based plastics.

An interesting candidate for replacing many types of plastic is transparent wood. Transparent wood is a man-made material derived from natural wood. Wood has three components: cellulose, hemicellulose, and lignin. Transparent wood is created by removing the lignin and hemicellulose, leaving behind a porous, paper-like network of cellulose. It is transparent but lacks structural strength. In the past, clear materials like epoxies have been added to produce a strong, transparent material: transparent wood. But because of the epoxy – itself a form of plastic – the resultant material was non-biodegradable.

Researchers at Kennesaw State University in Georgia have developed a method for producing transparent wood that replaces epoxies with an egg white and rice extract mixture along with a curing agent called diethylenetriamine. The end product is a semi-transparent form of wood that is biodegradable.

The researchers also incorporated silver nanowires into samples of their transparent wood. This enabled the wood to conduct electricity and could be useful in wearable sensors or as coatings for solar cells. There is additional research needed to improve the properties of this transparent wood, but a plastic replacement made from natural and inexpensive materials could be quite valuable.

**********

Web Links

Making sturdy, semi-transparent wood with cheap, natural materials

Photo, posted August 1, 2017, courtesy of NOAA Marine Debris via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Transparent Wood | Earth Wise

June 14, 2021 By EarthWise Leave a Comment

In recent years, there have been efforts to change the nature of wood to give it new properties. People have demonstrated so-called augmented wood with integrated electronics, energy storage capabilities, and other properties. Several different groups of researchers have developed wood that is actually transparent.

In 2016, researchers at KTH Royal Institute of Technology in Stockholm demonstrated transparent wood made by selectively extracting lignin – the substance that makes up the cell walls of wood -and replacing it with a polymer. The result is a new material that is weatherproof, fairly fire resistant, stronger than wood, lighter than wood, and transparent.

When the lignin is removed from wood, the empty pores left behind need to be filled with something that restores the wood’s strength. The early versions of transparent wood used polymethyl methacrylate – essentially acrylic plastic – for this purpose. But that material is made from petroleum, so it is not an environmentally desirable approach.

Recently, the KTH researchers have successfully tested an eco-friendly alternative: limonene acrylate, which is a monomer made from renewable citrus, such as peel waste that can be recycled from the orange juice industry.

There are many potential applications for transparent wood as a structural material. These include load-bearing windows, skylights, and semi-transparent facades that are strong and thermally insulating and yet permit light to enter.

Transparent wood would be a very attractive material for many applications in that it comes from renewable sources and offers excellent mechanical properties including strength, toughness, low density, and low thermal conductivity.

**********

Web Links

Citrus derivative makes transparent wood 100 percent renewable

Photo, posted October 12, 2018, courtesy of Mussi Katz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.